What is a photon?

What is a photon?- The gigants of physics, A. Einstein and N. Bohr, could not agree on an answer to this question. Also both dialogue partners of this video cannot give a final, but a pragmatic answer and find an analogy in a piece of artwork in the Sculpture Park Wuppertal.

The properties of some hightech materials can be reversibly switched by irradiation with light. This is demonstrated in the video by an “intelligent” transparency, which contains a photoactice molecular switch. Its structure and properties are explained.

The mechanical equilibrium between forces is completely different from economic, ecologic and other equilibria. Also chemical equilibria can be very different. This is shown by experiments with molecular switches in this video.

According to an accepted doctrine, the structure of a dye determines the colour of its solution if the solvent itself is colourless. The experiments from this video show the contrary and the protagonists explain this phenomenon.

Underground Minigolf

Today, brilliant colours that only appear in UV light, are part of everybody´s everyday experience. Usually photons of higher energy are turned into photons of lower energy. In a fascinating experiment this video shows that this can also work vice versa, and gives a clear and convincing explanation.